using Health.Application.Auth;
using Health.Infrastructure.Services;

namespace Health.Infrastructure.Auth;

public sealed class AuthService(
    AppDbContext db,
    JwtProvider jwt,
    SmsService sms,
    AppleTokenValidator appleValidator  // Apple Sign-In JWT 验证
) : IAuthService
{
    private const string AdminPhone = "12345678910";
    private const string AdminSmsCode = "000000";
    private static readonly Guid AdminId = Guid.Parse("00000000-0000-0000-0000-000000000001");
    private readonly AppDbContext _db = db;
    private readonly JwtProvider _jwt = jwt;
    private readonly SmsService _sms = sms;
    private readonly AppleTokenValidator _appleValidator = appleValidator;

    public async Task<AuthResult> SendCodeAsync(string phone, bool revealDevelopmentCode, CancellationToken ct)
    {
        var code = phone == AdminPhone ? AdminSmsCode : _sms.GenerateCode();
        await _db.VerificationCodes.AddAsync(new VerificationCode
        {
            Id = Guid.NewGuid(), Phone = phone, Code = code,
            ExpiresAt = DateTime.UtcNow.AddMinutes(5),
        }, ct);
        await _db.SaveChangesAsync(ct);
        if (phone != AdminPhone) await _sms.SendCodeAsync(phone, code);
        return new AuthResult(0, new { success = true, devCode = revealDevelopmentCode ? code : null });
    }

    public async Task<AuthResult> RegisterAsync(RegisterCommand command, CancellationToken ct)
    {
        var code = await TakeCodeAsync(command.Phone, command.SmsCode, ct);
        if (code == null) return Error(40001, "验证码错误或已过期");
        if (await _db.Users.AnyAsync(x => x.Phone == command.Phone, ct)) return Error(40002, "该手机号已注册，请直接登录");
        if (string.IsNullOrWhiteSpace(command.Name)) return Error(40003, "请输入姓名");
        if (!await _db.Doctors.AnyAsync(x => x.Id == command.DoctorId && x.IsActive, ct)) return Error(40004, "所选医生不存在或已停诊");

        code.IsUsed = true;
        var user = new User
        {
            Id = Guid.NewGuid(), Phone = command.Phone, Role = "User", Name = command.Name,
            DoctorId = command.DoctorId, CreatedAt = DateTime.UtcNow, UpdatedAt = DateTime.UtcNow,
        };
        _db.Users.Add(user);
        _db.NotificationPreferences.Add(new NotificationPreference { Id = Guid.NewGuid(), UserId = user.Id });
        _db.HealthArchives.Add(new HealthArchive { Id = Guid.NewGuid(), UserId = user.Id });
        var tokens = AddTokens(user.Id, user.Phone, user.Role);
        await _db.SaveChangesAsync(ct);
        return new AuthResult(0, new { tokens.accessToken, tokens.refreshToken, user = new { user.Id, user.Phone, user.Role, isNew = true } });
    }

    public async Task<AuthResult> LoginAsync(string phone, string smsCode, CancellationToken ct)
    {
        var code = await TakeCodeAsync(phone, smsCode, ct);
        if (code == null) return Error(40001, "验证码错误或已过期");
        code.IsUsed = true;

        if (phone == AdminPhone)
        {
            var tokens = AddTokens(AdminId, AdminPhone, "Admin");
            await _db.SaveChangesAsync(ct);
            return new AuthResult(0, new { tokens.accessToken, tokens.refreshToken, user = new { id = AdminId, phone = AdminPhone, role = "Admin", name = "管理员", isNew = false } });
        }

        var user = await _db.Users.FirstOrDefaultAsync(x => x.Phone == phone, ct);
        if (user == null) return Error(40004, "该手机号未注册，请先注册");
        user.UpdatedAt = DateTime.UtcNow;
        var userTokens = AddTokens(user.Id, user.Phone, user.Role);
        await _db.SaveChangesAsync(ct);
        return new AuthResult(0, new
        {
            userTokens.accessToken, userTokens.refreshToken,
            user = new { user.Id, user.Phone, user.Role, user.Name, user.Gender, user.AvatarUrl, BirthDate = user.BirthDate?.ToString("yyyy-MM-dd"), isNew = false }
        });
    }

    public async Task<AuthResult> RefreshAsync(string refreshToken, CancellationToken ct)
    {
        var oldToken = await _db.RefreshTokens.FirstOrDefaultAsync(x => x.Token == refreshToken && !x.IsRevoked, ct);
        if (oldToken == null || oldToken.ExpiresAt < DateTime.UtcNow) return Error(40002, "登录已过期，请重新登录");
        oldToken.IsRevoked = true;

        if (oldToken.UserId == AdminId)
        {
            var tokens = AddTokens(AdminId, AdminPhone, "Admin");
            await _db.SaveChangesAsync(ct);
            return new AuthResult(0, new
            {
                tokens.accessToken,
                tokens.refreshToken,
                user = new
                {
                    id = AdminId,
                    phone = AdminPhone,
                    role = "Admin",
                    name = "管理员"
                }
            });
        }

        var user = await _db.Users.FindAsync([oldToken.UserId], ct);
        if (user == null) return Error(40002, "用户不存在");
        var userTokens = AddTokens(user.Id, user.Phone, user.Role);
        await _db.SaveChangesAsync(ct);
        return new AuthResult(0, new
        {
            userTokens.accessToken,
            userTokens.refreshToken,
            user = new
            {
                user.Id,
                user.Phone,
                user.Role,
                user.Name,
                user.Gender,
                user.AvatarUrl,
                BirthDate = user.BirthDate?.ToString("yyyy-MM-dd")
            }
        });
    }

    public async Task LogoutAsync(string refreshToken, CancellationToken ct)
    {
        var token = await _db.RefreshTokens.FirstOrDefaultAsync(x => x.Token == refreshToken, ct);
        if (token != null) token.IsRevoked = true;
        await _db.SaveChangesAsync(ct);
    }

    public async Task<AuthResult> AppleLoginAsync(AppleLoginCommand command, CancellationToken ct)
    {
        // 1. 验证 Apple identityToken
        string appleUserId;
        try
        {
            appleUserId = await _appleValidator.ValidateAsync(command.IdentityToken, ct);
        }
        catch (OperationCanceledException) when (ct.IsCancellationRequested)
        {
            throw;
        }
        catch (Exception)
        {
            return Error(40005, "Apple 登录验证失败，请重试");
        }

        // 2. 查找已有用户
        var existingUser = await _db.Users.FirstOrDefaultAsync(x => x.AppleUserId == appleUserId, ct);
        if (existingUser != null)
        {
            existingUser.UpdatedAt = DateTime.UtcNow;
            if (!string.IsNullOrWhiteSpace(command.Name)) existingUser.Name ??= command.Name;
            var tokens = AddTokens(existingUser.Id, existingUser.Phone, existingUser.Role);
            await _db.SaveChangesAsync(ct);
            return new AuthResult(0, new
            {
                tokens.accessToken, tokens.refreshToken,
                user = new { existingUser.Id, existingUser.Phone, existingUser.Role, existingUser.Name, existingUser.Gender, existingUser.AvatarUrl, isNew = false }
            });
        }

        // 3. 新用户 → 创建账户（无需手机号、无需选医生）
        var newUser = new User
        {
            Id = Guid.NewGuid(),
            Phone = null,
            AppleUserId = appleUserId,
            Role = "User",
            Name = command.Name,
            CreatedAt = DateTime.UtcNow,
            UpdatedAt = DateTime.UtcNow,
        };
        _db.Users.Add(newUser);
        _db.NotificationPreferences.Add(new NotificationPreference { Id = Guid.NewGuid(), UserId = newUser.Id });
        _db.HealthArchives.Add(new HealthArchive { Id = Guid.NewGuid(), UserId = newUser.Id });
        var newTokens = AddTokens(newUser.Id, null, newUser.Role);
        await _db.SaveChangesAsync(ct);
        return new AuthResult(0, new
        {
            newTokens.accessToken, newTokens.refreshToken,
            user = new { newUser.Id, Phone = (string?)null, newUser.Role, newUser.Name, isNew = true }
        });
    }

    private Task<VerificationCode?> TakeCodeAsync(string phone, string code, CancellationToken ct) =>
        _db.VerificationCodes.Where(x => x.Phone == phone && x.Code == code && x.ExpiresAt > DateTime.UtcNow && !x.IsUsed)
            .OrderByDescending(x => x.CreatedAt).FirstOrDefaultAsync(ct);

    private (string accessToken, string refreshToken) AddTokens(Guid userId, string? phone, string role)
    {
        var access = _jwt.GenerateAccessToken(userId, phone ?? "", role);
        var refresh = _jwt.GenerateRefreshToken();
        _db.RefreshTokens.Add(new RefreshToken { Id = Guid.NewGuid(), UserId = userId, Token = refresh, ExpiresAt = DateTime.UtcNow.AddDays(30) });
        return (access, refresh);
    }

    private static AuthResult Error(int code, string message) => new(code, null, message);
}